Frame transferring mechanism and drive therefor



ll, 1933 7 Sheets-Sheet l INVENTOR.

ATTORNEY.

Julius Bffiedemann Nov. 15, 1938. J. B. TIEDE'MANN FRAME TRANSFERRINGMECHANISM AND DRIVE THEREFOR Original Filed.Deo.

ii an J. B. TIEDEMANN 2,136,477

TRANSFERRING MECHANISM AND DRIVE THEREFOR Nov. 15, 1938.

FRAME Original Filed Dec. ll, 1953 Sheets-Sheet 2 h \9 Q v e E 21 v R Ew 1! H Q 1]! o 12 I E") 1 5" E 3 l Q A Q a u] \O Q: n E m T u T I:

k 1'. o In N Julius B.Tiedemann INVENTOR.

BY 4am ATTORNEY.

Nov. 15, 1938. J. B. TIEDEMANN FRAME TRANSFERRING MECHANISM AND DRIVETHEREFOR Original Filed Dec.

11, 1953 '7 Sheets-Sheet 3 illlllll Julius Bl'iedemann INVENTOR.

ATTORNEY.

Nov. 15, 1938.

J. B. TIEDEMANN FRAME TRANSFERRING MECHANISM AND DRIVE THEREFOR OriginalFiled .Dec. 11, 1953 '7 Sheets-Sheet 4 INVENTOR.

ATTORNEY.

Julius BQTiecIemann Nov. 15, 1938. J. B. T'IEDEMANN FRAME TRANSFERRINGMECHANISM AND DRIVE THEREFOR Original Filed Dec; '7 Sheets-Sheet 5Julius B.Tieclemann ATTORNEY.

Nov. 15, 1938. .1. B. TIEDEMANN FRAME TRANSFERRING MECHANISM AND DRIVETHEREFOR Original Filed 050. 11, 1955 7 Sheets-Sheet e JuliusB.Tieclemann I INVENTOR. BY 0 Z W ATTORNEY.

Nov. 15, 1938. J. B. TIEDEMANN 2,136,477

- FRAME TRANSFERRING MECHANISM AND DRIVE THEREFOR Original Filed Dec.ll, 1953 v She'ets-Shet 7 Julius B. Tzedemcmn INVENTOR.

ATTORNEY.

Patented Nov. 15, 1938 UNITED STATES PATENT OFFICE FRAME TRANSFERRINGMECHANISM AND' DRIVE THEREFOR Original application December 11, 1933,Serial No. 701,842, new Patent No. 2,057,351.

Divided and this application September 12,1936, Serial 7 Claims.

The invention relates to improvements in frame transferring mechanismand drive therefor, and has found specific embodiment in. an apparatusemployed in the manufacture of automobile frames. The system andapparatus for the manufacture of the frames constitutes a semiautomaticplant embodying the general principles and features of the United StatesLetters Patent No. 1,397,020, issued to R. Stanley Smith, 0 and ofseveral improvement patents all of which have been assigned to the A. O.Smith Corporatlon.

The present invention embodies an improvement in frame transferringmechanism designed to transfer the partially assembled frame structuresto an assembling machine and to remove the assembled frame from themachine.

The frames are partially assemble-d on conveyor trucks and carriedthereon to the transfer mechanism which removes the frame elements froma truck while retaining their relative positions and deposits theelements in the same relative position upon the supports of theassembling machine. This machine then assembles the ele- 2 ments into aunitary frame and inserts rivets in aligned openings in the severalparts to temporarily secure the elements together. The transfermechanism then removes the assembled frame and deposits the same upon aconveyor truck which subsequently transports the frame to a plurality ofstations where riveting machines are caused to set the various rivets tocomplete the frame as more fully described in co-pending applicationSerial No. 501,301, filed December 10, 1930, by Birg-er T. Andren andJulius B. Tiedemann and assigned to the same assignee. as the presentcase.

The present application constitutes a division of application Serial No.701,842, filed December 11, 1933 for Frame transferring mechanism anddrive therefor, on which Patent No. 2,057,351 was granted October 13,1936.

The principal object of the invention is to provide a transfer mechanismfor the purpose intended which is simple in construction and which hasfew wearing parts, thereby making repair and upkeep less expensive. v

Another object is to provide such an apparatus which will substantiallyincrease the rate of production and allow the employment of a muchshorter working cycle of operation.

Another object is to provide a new type of drive for the transfermechanism which will greatly increase the speed of operation and whichwill also eliminate objectionable vibration and provide a smoothoperation having the proper timed cycles for each function of themachine.

Other objects will appear hereinafter in connection with the moredetailed description of the preferred embodiment of the inventionillustrated in the accompanying drawings.

Figure 1 of the drawings is a transverse section of the mechanismshowing schematically apparatus with which it is employed;

Fig. 2 is a side elevation of the same mechanism;

Fig. 3 is an enlarged vertical section of the transfer mechanism, alone,in its raised position, on line 3-3, of Fig. 2;

Fig. 4 is a similar sectional view of the transfer mechanism in itslowered position;

Fig. 5 is a top plan view of one end of the transfer mechanism;

Fig. 6 is a perspective view of the carriage showing the clamping andlifting mechanism thereon;

Fig. '7 is an enlarged detail sectional view taken on the line 1-4 ofFig. 5;

Fig. 8 is a top plan view of the drive for the machine;

Fig. 9 is a vertical section on line 9-9 of Fig. 8 showing the drive forthe carriage transfer and certain of the cam drives in one position inthe cycle of operation;

Fig. 10 is a section similar to Fig. 9 showing the drive in the oppositeposition of operation in the cycle;

Fig. 11 is a vertical section on line ll--ll of Fig. 8 showing the drivefor elevating the carriage, and certain of the cam drives in oneposition in the cycle of operation; and

Fig. 12 is a section similar to Fig. 11 showing the drive in theopposite position of operation in the cycle. v

The machine comprises, in combination with a conveyor system, a transfermechanism, assembling mechanism, rivet supplying and driving mechanism,and a single drive for the various elements.

The conveyor system which supplies the parts to be assembled and carriesaway the assembled frame may be of any suitable design. That shown inthe drawings comprises two separate systems, one for bringing the partsto be assembled to the machine, and the other for taking the assembledframes away.

In general, the conveyor for supplying parts to the machine comprises aright-hand set of parallel rails l and a left-hand set of parallel rails2, each set providing a conveyor track uponwhich the trucks 3 aremounted for intermittent movement. The trucks 3 are transferred from oneset of rails to the other at the ends of the rails by means of screwconveyors 4 operating from the same drive as that for the trucks on thetrack and providing a closed circuit or path for movement of the trucks.

The trucks 3 have individual adjustable supports 5 thereon for receivingthe various frame elements in juxtaposed relation for assembly. As thetrucks 3 pass intermittently along the rails I toward the assemblymachine, workmen posted at the various stations along the rails placethe several frame elements in position on the trucks. When the truck hasreceived a complete frame and reached the end of the rails I, it istransferred laterally toward the assembly machine to the end of the setof rails 2, by means of the screw conveyors 4.

The frame transfer mechanism, as more fully described hereinafter, thenpicks up each individual frame element from the truck 3 and deposits itin the assembly machine, leaving the truck 3 empty. The empty truck thenpasses down rails 2 to the other end of the conveyor line where it istransferred to rails I by means of screw conveyors operating in the samemanner as the screw conveyors 4 shown in the drawings at the end of thetrack adjacent the assembly machine.

In general, the conveyor for removing assembled frames from the machineis constructed similar to that just described and embodies two sets ofrails 6 and 1 upon which a plurality of trucks 8 are mounted forintermittent movement. Screw conveyors 9, only one of which is shown,are also provided at the ends of the rails for transferring the trucksfrom one set to the other in the same manner as that previouslydescribed. The adjustable supports ID on each truck are adapted toreceive the assembled frame and hold it during transport.

The conveyor systems, "generally described above, may be constructed inany suitable manner, or eliminated and other suitable means provided forperforming the functions described.

The assembling mechanism, with which the present invention finds itsuse, may have various details of construction depending upon thestructure to be assembled. The mechanism illus trated diagrammaticallyin the drawings is for use in assembling automobile frames.

The frame transferring mechanism comprises, in general, a verticallymovable track II, a horizontally movable truck I2 mounted on the trackII, and transfer carriages I3 and I4 carried by the truck.

The vertically movable track II comprises two parallel rails extendingacross the entire machine and across the sets of conveyor rails 2 and I,one at each end of the machine. Each rail is supported on two screwjacks I5 and the rails may be raised or lowered by operation of thesejacks.

The rails are additionally supported by means of a plurality of aircushion cylinders I8 which serve to cushion the downward movement of therails and to facilitate raising the rails. In the preferred embodimentillustrated, four cylinders I6 are provided for each rail and aredistributed about equally apart along the rail. to properly balance thelatter whether the truck I2 is at one end or the other of the rails.

The truck I2 comprises a rectangular frame having side bars I! and twotubular cross bars I8. Wheels I9 support the truck on the track E I.

The carriage i3 is suspended from one tubular cross bar I8 while thecarriage I4 is suspended from the other tubular cross bar I8.

The carriage I3 comprises two bars 23 and iii extending parallel to therespective cross bar i8. The carriage bars 26 and 2I are suspended ateach end by links 22 hanging from a yoke 23 fixed to the correspondingend of the respective cross bar I8. The mode of supension is such thatone bar 20 of carriage I3, for instance, is suspended from the yokes 23on one side of the cross bar I8, and the other bar 2! of the carriage issuspended from the yokes 23 on the other side of the cross bar I8, thebars tending to balance each other. The links 22 allow relative movementof the bars 20 and HI toward and away from each other as will beexplained hereinafter.

Carriage I4 is constructed similarly to carriage I3 and comprises twobars 24 and 25 suspended by means of links 23 from the fixed yokes 2'!on the other cross bar I8. The links 26 support the bars 24 and 25 forrelative movement toward and away from each other as will be explainedhereinafter.

The carriage I3 is adapted to carry the frame parts from a conveyortruck 3 and to deposit the parts upon the supports of the-assemblingmachine. The carriage I4 is adapted to carry the assembled frame 28 fromthe assembling machine and to deposit it upon the supports I 6 of thetruck 8.

Carriage I3 is provided with a plurality of clamps mounted on the bars26 and 2|. The clamp 29 for carrying a cross bar of the automobileframe, for instance, comprises a depending hook 30 mounted on bar 26 andadapted to hook into one end of the cross bar, and a similar dependinghook 3I mounted on bar 2| and adapted to hook into the other end of thecross bar. The hooks 30 and 3 I are controlled by relative movement ofbars 25 and 2| toward and away from each other to cooperate in clampingor releasing the cross bar, as desired.

The clamps 32 for carrying the side bars of the automobile framecomprise a pair of parallel transverse rods 33 and 34 having downwardly"extending prongs at each end. Rod 33 is attached to bar 26 while rod 34is attached to bar 2|. The prongs 35 at the right-hand ends of the rods33 and 34 are offset so that, as the carriage I3 is lowered over a truck3, the prongs 35 on rods 33 will pass down on the right-hand side of theright-hand side bar while the prongs 35 on rods 34 will pass down on theleft-hand side of the same side bar. Subsequent relative movement of thebars 20 and El toward each other Will effect a clamping of the side barbetween the prongs 35. One of the prongs 35 has a lateral extension 36for passing under the side bar to prevent its accidental release fromthe clamp.

The left-hand side bar is clamped by means of prongs 31 mounted at theleft-hand ends of rods 33 and 34 in a manner similar to the clamping ofthe right-hand side bar as just described.

The various parts of the clamps 29 and 32 are all adjustabiy mounted soas to accommodate any size, shape, or position of frame element.

Figure 1 illustrates the carriage I3 in position over a truck 3 with theseveral clamps 29 and 32 closed upon the respective frame elements. Thisclosing of the clamps is accomplished simultaneously by movement of bars29 and 2i toward each other. In the next step the carriage I3 is raiseda predetermined amount by elevating the track thereby lifting the frameelements from the truck 3. The carriage |3 is then moved laterally asillustrated in Fig. 3 to a position over the assembling machine bylateral movement of the truck |2 along the track N. Then the carriage i3is lowered, as shown in Fig. 4, to position the several frame elementsupon the supports of the assembling machine. The bars 29 and 2| are thenmoved apart to open the clamps 29 and 32 and release the frame elements.The carriage is then raised and returned empty to a position overanother truck 3 for picking up another group of frame'elements.

:During the transfer of a group of frame elements, they are maintainedin the same predetermined relative position as provided in theirplacement on the trucks 3 so that after their deposit on the supports ofthe assembling machine, they are ready for immediate assembly.

The adjustable depending hooks 38 mounted on bar 24 and similar hooks 39mounted on bar 25 are adapted to cooperate in picking up an assembledframe 23 and carrying the same to the truck 8. As shown, hooks 38mounted on the right-hand bar 24 are adapted to lift the lefthand sideof the frame 28 while hooks 39 mounted on the left-hand bar 25 areadapted to lift the right-hand side of the frame. By this arrangementthe hooks 38 and 39 are adapted to pick up a frame when the bars 24 and25 are moved away from each other and to release a frame when the bars24 and 25 are moved toward each other.

Fig. 1 illustrates the carriage l4 over the assembling machine with thehooks 38 and 39 in position for lifting the assembled frame 28. The nextstep is that of raising the carriage I4 and with it the frame 2.8 byraising the track Thereafter the carriage is transferred to the left toa position over a truck 8 by lateral movement of the truck l2 along thetrack The track H is then lowered to effect a lowering of the assembledframe onto the supports |9 of the truck 8. The hooks 38 and 39 are'thenseparated to release the frame by moving the bars 24 and 25 toward eachother, and the carriage I4 is raised and returned empty to a positionabove the assembling machine.

Since both carriages l3 and M are suspended from truck I 2, the cycle ofoperation of each carriage is identical with that of the other, so thatboth carriages are lowered simultaneously, one to pick up frameelements, and the other to pick up an assembled frame. Both carriagesare then raised simultaneously and transferred to the left where bothare again lowered, this time to release their respective loads, afterwhich they are i again raised and transferred simultaneously back toposition for lowering and loading.

By reason of this simultaneous cycle of operation of the carriages l3and 4, it is possible to provide a single means for driving all of theclamps and hooks in unison. This is accomplished by providing, at eachend of the carriages, a tube 4|] connecting the inner bars 2| and 24 anda longer tube 4| slidably mounted in the tube 40 and connecting theouter bars 20 and 25. Relative longitudinal movement of the tubes 49 and4| will effect a relative movement of the carriage bars 2|) and 2|toward or away from each other, as the case may be, and a relativemovement of the carriage bars 24 and 25 away from or toward eachother,as the case may be,

the relative movement of bars 24 and 25 at any given time being oppositeto that of bars 29 and 2|.

The relative longitudinal movement of each set of tubes 49 and 4| iseffected by a link 42 secured to tube 40, as at 43, and a link 44secured to tube 4|, as at 45. The inner ends of links 42 and 44 arepivotally secured to levers 46 and 41, respectively, which are fulcrumedat their centers to the truck bars H. The upper ends of the levers 4Band 41 are connected by short toggle links 48 and 49, respectively, tothe opposite ends of a rocker beam 59. The rocker beam 59 is secured toone end of a short pivot shaft 5| which extends through the side bar I!of the truck l2. An arm 52 having a roller 53 on its free end isattached to the outer end of the shaft 5|.

Operation of the arm 52 to the right as shown in Fig. 1 will effect arelative movement of bars 20 and 2| toward each other and of bars 24 and25 away from each other to effect the desired clamping operations, whilemovement of the arm 52 to the left will effect a reverse movement of thebars and a release of the clamping members.

Operation of the arm 52 is effected only at the time when the truck i2is lowered to either pick up a load or to release a load. That is, arm52 is moved tothe right when the truck is at the right-hand side of themachine and lowered ready to pick up a load, and'the arm 52 is moved tothe left when the truck is at the left-hand side of the machine andlowered ready to release its load. This movement of thearm 52 iseffected by a horizontal reciprocating rod 54 having upright channelmembers 55 and 56 spaced horizontally thereon a distance equal to thelateral movement of truck I2. When the truck I2 is in its extremeright-hand position and lowered to pick up a load, the roller 53 engagesin the channel 55. Movement of the rod 54 to the right then effectsmovement of the arm 52 to the right. When the truck I2 is in its.extreme left-hand position and lowered to release its lead, the roller53 engages in the channel 55. Movement of the rod 54 to the left theneffects movement of the arm 52 to the left.

The reciprocation of the rod 54 to the left or right at the requiredtime in synchronism. with the machine to obtain the desired clamping andrelease of frame members is obtained by suitable connections of the rod54 to a link 51 operated by the continuously rotating cam disk 58, aswill be explained hereinafter.

The arm 52 is, at all times during movement of the truck l2, lockedeither in its left or righthand position, in order to prevent accidentaloperation of the clamping members on the carriages l3 and M and droppingof frame elements. This locking of the arm 52 is obtained by a verticalrib 59 on a cross head 60 at each end of the truck I2. The roller 53 isadapted to ride on either side of the rib 59 whenever the truck I2 israised sufficiently to disengage the roller from either of the channels55 and 5B. Thus, after leaving the channel 55 on the right side of therib 59, the roller 53 will stay on the right side of the rib until it islowered into the channel 56, and vice versa, when the roller 53 leavesthe channel 56 on the left side of the rib 59, it will stay on the leftside of the rib until lowered into channel 55.

The truck I2 is moved laterally by means of the cross heads 60 whichride in horizontal guides 6|. Each of the side bars I! of truck l2 has aguide member 62 provided with a groove 63 for receiving the vertical rib59 on a cross head 60. Vertical movement of the truck I2 on rails IIdoes not release the grooves 83 from the ribs 59, and so the lateralposition of the truck I2 is controlled at all times by the cross heads60.

The cross heads Gil do not move vertically, but are moved horizontallyin their guideways 6| by means of links 64 and crank arms 65 attached toa shaft 66 extending longitudinally of the machine at the right-handside. A gear segment 61 is provided on the shaft 96 for driving thecrank arms 65 through a predetermined rotary movement and reverse.

In order to facilitate acceleration and retardation of the cross heads69 and lateral movement of the truck I2, an air-pressure cylinder 68 isprovided at each side of the machine. A piston 69 operates in eachcylinder to retard or accelerate the shaft 60 as its crank arms 65 arerotated to or away from their extreme positions in either direction.Each piston 09 is connected by a rod I0 to a crank arm 'II on the shaft90. The air pressure in the cylinders is varied to suit differentoperating speeds and is preferably supplied from a suitable source ofair pressure of large volume connected with the cylinders.

Having described the transfer mechanism in detail, the mechanism fordriving the several parts will now be described. The drive mechanism maybe divided into three general parts, although all are driven from asingle common source of power so as to maintain synchronism of operationbetween the several parts. The three general parts of the drivemechanism are: the various cam drives for the assembling mecha nism, forthe rivet supply and driving mechanism, and for operating the carriageclamps; the crank drive for moving the truck I2 laterally; and the crankdrive for raising and lowering the truck I2.

The several parts of the mechanism are driven from the main drive shaftI2 which is continuously rotated by a suitable source of power such asan electric motor or an engine (not shown).

The chief problems involved in designing the several parts of the drivemechanism, apart from that of properly timing and synchronizing theseveral parts of the entire machine, are to insure the least vibrationpossible and to obtain as rapid acceleration and deceleration of theseveral masses to be moved as possible consistent with smoothness ofoperation. The magnitude of these problems will be appreciated when itis realized that the total time for one complete cycle of operation ofthe entire machine is about seven seconds and that during that time manyof the parts have to be accelerated and retarded twice as well as tohave the requisite periods of dwell for operation of other parts.

The main drive shaft I2 is connected through suitable reduction gearingI3 to drive a shaft 14 upon which the cam 58 is mounted and which alsooperates the crank drive for moving the truck I2 laterally. The maindrive shaft I2 is also connected through another train of reductiongearing 15 to drive a shaft T6 which operates the crank drive for movingthe truck I2 vertically. The reduction obtained by gear trains I3 and I5have the ratio of 2 to 1, thereby resulting in the driving of shaft I4at one-half the speed of shaft I6. Shafts I4 and I9 are driven inopposite directions.

The cam drives for the assembling machine proper are mounted on shaft I4adjacent the cam 58 and are illustrated only diagrammatically as at 11.

Cam disk 58 has a cam groove I8 in one side which coacts with roller I9carried on a horizontal pivoted arm near the free end thereof. The link51 is pivoted to the free end of arm 80 and extends upwardly therefrom.The upper end of link 51' is pivoted to the end of a crank 8I whichrotates the horizontal stub shaft 82. The shaft 82, through suitablebevel gears 83, rotates a horizontal shaft 84 which, through bevel gears85, rotates a vertical shaft 86 at each side of the machine. Each shaft86 has a crank 81 at its upper end connected by means of the link 51 tothe reciprocating rod 54.

The cam groove I8 is designed to raise the arm 80 and link 51 and tomaintain them raised during approximately one-half of the revolution ofshaft I4, and then to lower them during the remaining half of therevolution, to effect the desired closing and opening of the clampingelements on the carriages I3 and I4.

The crank drive for moving the truck I2 laterally on the track IIcomprises, in general, the driving crank 88 attached to shaft 14, aplurality of arms pivoted on a common axis and connected together bymeans of toggle links which have their central pivots engaging a camtrack, and suitable gearing driven by a gear segment on one of the arms.

In the construction shown, the crank 88 is connected to one pivoted arm89 by means of a long connecting rod 90. A second arm 9| is pivoted at92 in common with arm 89 and has its outer end connected by means of thetoggle links 93 to the lever 89 at the point 94 Where the connecting rodis pivoted to the lever 89. The central pivot 95 between the togglelinks 93 is provided with rollers 95 on each side adapted to ride in camtracks 9'1 provided in the stationary side plates 98. The links 93extend to the right from the arm 89 toward the crank 88, thesignificance of which will be pointed out later.

The arm 9i has an extension to the left of the lever 89 providing aconnection for a second pair of toggle links 99 which connect arm 9|with the end of a gear segment I00 to the left of said arm 9|. The gearsegment I90 is also pivoted at 92. The second pair of toggle links 99have a central pivot IOI provided on both sides with rollers I02 whichride in the cam tracks 91.

The gear segment I00 is connected by suitable gearing I03, shaft I04 andpinion I05 to drive the gear segment 61 on the shaft 66 to move thetruck I2 laterally.

The problem in designing the above mechanism was to provide for therequiring dwell or rest period for the truck 12 at each end of itslateral stroke and at the same time obtain a rapid acceleration tomaximum speed and retardation from such speed. To this end the cam track91 was designed as shown with its central portion followingsubstantially concentric to pivot point 92. The end portions of the camtrack are curved differently, as will be pointed out hereinafter.

It will be noted that the dwell produced at the left end of the strokeis effected by a combination of or coaction between the crank 88, whichis passing dead center, the toggle 99 which closes at this time, and thecrank 65 which is also at dead center. The curvature of the cam track 91at its end determines the length of time of the dwell period beyond thatnormally obtained from the dead centers of cranks 88 and 65. It will beappreciated that truck I 2 must be given suificient time to lower andrise at the end of its stroke before resuming its return stroke.

The rapid acceleration of truck I2 is effected after a period of rest bythe crank 88 passing dead center and starting to increase its powerstroke, the toggle 99 becoming straightened and rapidly moving thesegment I09 and the crank 65 passing its dead center and increasing itsstroke.

Figure 10 illustrates the parts,shown in Fig. 9, at the other end of thestroke after retardation where the crank 88 is on its opposite deadcenter, the toggle 93 is closed by the end curvature of camtrack 91 andthe crank 95 is on its opposite dead center.

In order to obtain the full benefit of the closing of either toggle atthe end of the stroke, it is preferable that the other toggle remainfully open at such time. The drawing Fig. 9 shows toggle 93 open andlying in the circular central portion of cam track 91 when the toggle 99is closed by the outer curvature of the left end of the cam track, whileFig. 10 shows the toggle 99 open and lying in the circular centralportion of the cam track 91 when the toggle 93 is closed by the outercurvature of the right end of the cam track.

The exact curvature at the ends of cam track 91 will depend upon thedimensions of the several parts and the dwell period desired at the endsof the strokes.

The left end of the cam track 91 is curved on a shorter radiusconcentric with the pivot point I96 on the gear segment I90, when thecrank 98 is at the left, and the right end of the cam track 9'! iscurved on a radius concentric with the pivot point In! on the arm 9|when the crank 88 is at the right. The proportion of length of the camtrack 91 constituted by the central curved portion largely determinesthe period of drive, while the proportion of the cam track 91constituted by the curved portion at each end determines the period offixed dwell at the respective end of the stroke.

During the time that the pivot rollers I02 are riding in the left-handportion of the cam track 91, the toggle link 99 merely closes or opens,depending upon the direction of movement of the arm 9|, and it does notat that time effect any movement of the gear segment I09. Furthermore,the gear segment I99 is locked against movement at this time by the leftarm of the toggle 99 .and the pivot rollers I92 riding in the cam track91.

When the crank 88 is at its right-hand position and the toggle pivotrollers 99 are riding in the curved right-hand portion of cam track 91,the toggle link 93 functions merely to open and close without moving thearm 9| and at the same time looking the arm 9| against movement. Thelocking of arm 9| against movement effects a locking of gear segment Iand prevents operation of the conveyor truck laterally.

The broken lines I98 in Fig. 9 illustrate the position of crank 88 atwhich the pivot rollers I02 enter and leave the left-hand portion of camtrack 91, thus illustrating the length of the dwell period in relationto the rotary movement of the crank 88. Similar lines could be drawn atthe right side to illustrate the period of dwell when the crank 88 is atthe right.

The shape of the cam track 91 in its central portion need not beconcentric to the pivot point 92, but it may be flattened or it may becurved more sharply so as to control the rate of acceleration andretardation of the driven element in any desired manner.

The crank drive for operating the screw jacks I5 and elevating orlowering the tracks I is very similar to that just described for movingthe trucks I2 laterally. The drive is operated from crank I09 on shaftI6, which, as pointed out before, is rotated twice as fast as shaft 14and in the opposite direction. The details of the mechanism are shown inFigs. 11 and 12.

The essential difference between it and the mechanism just describedlies in the fact that there is no crank corresponding to crank 65 forutilization of a dead center, and the period of dwell desired at one endof the stroke is longer than that at the other end. Furthermore, thecentral curved portion of the cam track is relatively short, thusproviding a short Working period for the drive. The dwell at theleft-hand end is short, providing time only for operation of thecarriage mechanism 30 to 39, inclusive, while the dwell at theright-hand end is long, providing time for the lateral transfer of thecarriages.

Consequently, the cam track I ID as illustrated in Figs. 11 and 12 has asubstantial curvature away from its circular path at the right end andonly a reasonably small outward curvature at the other end, each endportion being concentric to the respective pivot point of the togglelink at that end as previously described with respect to Figs. 9 and 10.Since the detail mechanism for this drive is practically the same as forthat described as to Figs. 9 and 10, it need not be described anew.

The gear segment II I of this drive is connected through suitable gearsII2, vertical shaft H3, gears IM, horizontal shafts H5, and gears M9 tothe vertical screw jacks I5 to drive the same.

The two crank drives are designed to cooperate in a manner providingoverlapping of movement of the tracks I! vertically and of the truck I2laterally, as illustrated by the arrows in Fig. 3 showing the path ofmovement of the carriages I3 and I4. This feature gives each movement alonger time of operation in a cycle of given time, and allows the cycleof operation to be shortened.

The preferred embodiment of the invention has been described in detailabove, but it will be understood that various embodiments may beemployed within the scope of the accompanying claims and withoutdeparting from the spirit and objects of the invention.

I claim:

1. In combination, a conveyor truck disposed for horizontalreciprocation and for vertical reciprocation through a cycle of loweringand rising at each end of the path of horizontal reciprocation, articleclamping means carried by the truck and disposed to grip an article whenthe truck is in its lowered position at one end of its horizontalreciprocation and to release the article when the truck is in itslowered position at the other end of its horizontal reciprocation, aconstantly rotating crank connected to reciprocate said truckhorizontally, a second constantly rotating crank operating insynchronism with said first crank and connected to reciprocate saidtruck vertically, means interposedbetween each of said cranks and thetruck for effecting a predetermined length of dwell of the truck betweensuccessive horizontal reciprocative movements and between successivecycles of vertical reciprocative movements, and means operating insynchronism with said cranks for effecting operation of said clampingmeans in timed relation to said reciprocative movements.

2. In combination, a conveyor truck disposed for reciprocation in apredetermined path of movement, article clamping means carried by thetruck and disposed to grip an article when the truck is at one end ofthe path of reciprocation and to release the article when the truck isat the other end of the path of reciprocation, a constantly rotatingcrank for reciprocating said trunk, means interposed between said crankand i said truck for modifying the movement produced by said crank toprovide predetermined periods of movement and of dwell for said truck tosome extent independent of the dead center positions of said crank, cammeans for effecting operation of said clamping means, and a constantlyrotating shaft for efiecting synchronized operation of said crank andsaid cam means.

3. In combination, a conveyor truck disposed for horizontalreciprocation and for vertical reciprocation through a cycle of loweringand rising at each end of the path of horizontal reciprocation, articleclamping means carried by the truck and disposed to grip an article whenthe truck is in its lowered position at one end of its horizontalreciprocation and to release the article when the truck is in itslowered position at the other end of its horizontal reciprocation, aconstantly rotating crank connected to reciprocate said truckhorizontally, a second constantly rotating crank operating insynchronism with said first crank and connected to reciprocate saidtruck vertically, means interposed between each of said cranks and thetruck for effecting a predetermined length of dwell of thetruck betweensuccessive horizontal reciprocative movements and between successivecycles of vertical reciprocative movements, means operating insynchronism with said cranks for effecting operation of said clampingmeans in timed relation to said reciprocative movements, and means forlocking said clamping means in predetermined position during movement ofthe truck.

4. In combination, a conveyor truck disposed for horizontalreciprocation and for vertical reciprocation through a cycle of loweringand rising at each end of the path of horizontal reciprocation, articleclamping means carried by the truck and disposed to grip an article whenthe truck is in its lowered position at one end of its horizontalreciprocation and to release the article when the truck is in itslowered position at the other end of its horizontal reciprocation, aconstantly rotating crank connected to reciprocate said truckhorizontally, a second constantly rotating crank operating insynchronism with said first crank and connected to reciprocate saidtruck vertically, and means operating in synchronism with said cranksfor effecting operation of said clamping means in timed relation to saidreciprocative movements.

5. In combination, a conveyor truck disposed for horizontalreciprocation and for vertical reciprocation through a cycle of loweringand rising at each end of the path of horizontal reciprocation, articleclamping means carried by the truck and disposed to grip an article whenthe truck is in its lowered position at one end of its horizontalreciprocation and to release the article when the truck is in itslowered position at the other end of its horizontal reciprocation, andmeans for locking said clamping means against operation during movementof the truck.

6. In combination, a conveyor truck disposed for reciprocation, articleclamping means carried by the truck and disposed to grip an article whenthe truck is at one end of its reciprocative movement and to release thearticle when the truck is at the other end of its reciprocativemovement, means for reciprocating said truck and operating said clampingmeans in timed sequence, and means positioned by the initial movement ofthe truck for locking said clamping means against operation during theremaining movement of the truck.

7. In combination, a conveyor truck disposed for reciprocation in onedirection and for reciprocation in another direction at the oposite endsof the first named reciprocation, a constantly rotating crank connectedto reciprocate the truck in the first named direction, a secondconstantly rotating crank operating in synchronism with said first crankand connected to reciprocate said truck in the second named direction,and means interposed between said cranks and said truck for effecting apredetermined length of dwell of the truck between predeterminedreciprocative movements in said first named direction and betweenpredetermined reciprocative movements in said second named direction.

JULIUS B. 'I'IEDEMANN.

